1. Field of the Invention
The present invention relates generally to signal generators and more particularly to phase-locked signal generators.
2. Description of the Related Art
Phase-locked signal generators (often termed phase-locked loops) find broad use in the building blocks (e.g., receivers, transmitters, frequency multipliers, timers and clock recovery structures) of a variety of modern electronic systems (e.g., communications systems, data processing systems and video systems). In a significant number of these uses, the signal generators must be realized with integrated circuit fabrication techniques that are specifically directed to arrays of digital gates. Accordingly, it is often found that some of the conventional generator elements (e.g., loop filters and voltage-controlled oscillators) are excessively expensive to realize and that the resulting performance is sometimes less than desired.